Life Sciences Commons^™

Natural Noise Can Influence Bird Foraging And Vigilance Behavior, Kate Antonia Sweet

Boise State University Theses and Dissertations

Natural sounds are an often overlooked, yet important component of an animal’s habitat. The acoustic environment may be especially significant during foraging, because a noisy world can limit auditory surveillance. Here, we investigated how natural noise structures the foraging vigilance trade-off to understand how intense acoustic environments may have shaped antipredator behavior across the evolutionary past, and better inform conservation efforts in the present.

First, in Chapter 1, I directly compared the foraging and vigilance behaviors of captive song sparrows (Melospiza melodia) in anthropogenic and natural noise. We recorded foraging trials in 4 playback conditions (roadway traffic, whitewater …

Movements Of White-Headed And White-Backed Vultures, Teague K. Scott

Boise State University Theses and Dissertations

Vultures are the only obligate vertebrate scavengers, and as such provide crucial services as keystone species and support the health and function of ecosystems in which they live. African vultures are a diverse group, with nine species found throughout Sub-Saharan Africa, many with overlapping distributions. Unfortunately, African vultures are faced with numerous threats throughout their range that have led to significant population declines, some greater than 90%, in only three generations. Four of these species are currently listed as critically endangered, and three as endangered.

Despite the significant perils faced by African vultures, there are still significant knowledge gaps and, …

Prevalence Of Anticoagulant Rodenticides In Ferruginous Hawk Nestlings And Evaluation Of A Novel Method To Rapidly Assess Exposure, Ariana Joyce Dickson

Boise State University Theses and Dissertations

Anticoagulant rodenticides (ARs) are compounds commonly used to control rodent pests by inhibiting an enzyme critical for synthesis of clotting factors in their blood. Secondary and tertiary poisoning of non-target species frequently occur, especially of predators that consume rodents, including many species of raptors. Although raptor exposure to ARs has been documented on at least three continents, patterns, pathways and the sub-lethal effects of exposure are not well studied. This has created a substantial need to monitor the effects of ARs in free-living populations. I evaluated the prevalence of secondary, non-target exposure to anticoagulant rodenticides experienced by a predatory raptor, …

How Water Level And Irrigation Practices Affect Waterbird Community, Nesting, And Foraging Habitat Use On The Duck Valley Indian Reservation, Jamie L. Burke

Boise State University Theses and Dissertations

Loss of habitat continues to threaten all bird populations. Despite efforts for conservation of wetlands, waterbirds continue to face habitat threats especially in western North America where water resources are limited across the landscape. The White-faced Ibis (Plegadis chihi) is a colonial nesting waterbird of conservation concern that builds nests in emergent vegetation of freshwater wetlands throughout the western United States. An ibis breeding colony site located at the Blue Creek Wetland complex on Duck Valley Indian Reservation may face habitat threats in the future due to plans intended to increase irrigation water use efficiency. Plans include manipulation …

Effects Of Protective Nesting Site Properties On Gyrfalcon Breeding Success And Parental Investment In Western Alaska, Michael Thomas Henderson

Boise State University Theses and Dissertations

Habitat suitability for wildlife is defined at scales ranging from the landscape to an individual breeding site. Areas that fulfill habitat requirements for birds disproportionally maintain populations, and the identification of variables that distinguish optimal breeding sites helps to prioritize conservation. Nesting site characteristics that protect breeding raptors from harsh weather can promote a more favorable microclimate and increase breeding success, although previous attempts to understand this effect in breeding Gyrfalcons have yielded ambiguous results. Additionally, breeding adults incur substantial costs from the physical shielding of eggs and nestlings, particularly in the Arctic, and it is possible that protective properties …

Old Enemies With New Problems?: Investigating The Ecological Relationship Between Ridgway’S Hawk And The Parasitic Nest Fly Philornis Pici, Christine Deegear Hayes

Boise State University Theses and Dissertations

Modern conservation efforts tend not to focus on individual species, but rather on the entire ecosystem of a species in peril. Many ecological factors can affect a species’ ability to maintain healthy populations. Parasites, which derive nutrients at the expense of their hosts, can reduce host fitness and limit population growth, acting as biological controls in healthy ecosystems. The negative impacts of parasites on their hosts can be exacerbated by climate change and anthropogenic land-use practices in ways that may limit recovery or drive host species to extinction. Introduced parasitic nest flies in the genus Philornis (Diptera: Muscidae) are threatening …

Barn Owls (Tyto Alba) Crossing The Road - Examining The Interplay Among Occupancy, Behavior, Habitat Selection, And Roadway Mortality In Southern Idaho, Tempe Regan

Boise State University Theses and Dissertations

Barn Owls (Tyto alba) are killed by vehicle collisions in greater numbers than any other North American bird of prey. Interstate-84 (I-84) in southern Idaho, USA has among the world’s highest known rates of Barn Owl-vehicle collisions. Little is known about Barn Owl occupancy in this region, so it is unclear if owls are killed in proportion to their abundance, or if they are equally abundant in segments with lower mortality and somehow escape collisions. Furthermore, studies of Barn Owl movements and behavior are limited. I was interested in understanding (1) factors that affect Barn Owl occupancy in …

Earlier Nesting By A Predatory Bird Is Associated With Human Adaptations To Climate Change, Shawn Heath Smith

Boise State University Theses and Dissertations

Advancing growing seasons and prey abundance drive earlier breeding in dietary specialists because, ultimately, consumers benefit by timing their reproduction to coincide with peak prey abundance. The selective pressure to breed earlier may be lower for species that forage on diverse prey items that vary in abundance both spatially and temporally. The selective pressure may be reduced further if predators have access to a mosaic of habitats, each of which having different shifts in growing seasons. We studied whether earlier breeding of a predatory generalist, the American kestrel (Falco sparverius) nesting in a mosaic of habitat types was …

Pheomelanin Pigment Is Not An Indicator Of Feather Corticosterone Content In Diurnal Migratory Raptors In Idaho, Christopher Porterfield

Boise State University Theses and Dissertations

In some cases, pigmentation can be used as an indicator of measures of condition. In this study, I tested the relationship between reddish pheomelanin pigmentation and the amount of corticosterone, a hormone associated with stress, sequestered in the feathers. I predicted that with higher corticosterone in feathers individuals would exhibit increased brightness and reduced saturation of pheomelanin pigments in their feathers. I collected spectral data from feathers from American Kestrels (Falco sparverius), Cooper’s Hawks (Accipiter cooperii), and Sharp-shinned Hawks (A. striatus) during migration in southwestern Idaho over two years (2010-2011). After extracting corticosterone from …

An In-Depth Evaluation Of Otolith Zonation And An Ageing Comparison Of Otoliths, Scales, And Pectoral Fin Rays Of Redband Trout (Oncorhynchus Mykiss Gairdneri) And Bluegill (Lepomis Macrochirus), Dennis A. Daw

Boise State University Theses and Dissertations

Redband Trout (Oncorhynchus mykiss gairdneri), a native subspecies of Rainbow Trout residing east of the Cascade Mountains, USA, are a popular sport fish in much of its range. Bluegills (Lepomis macrochirus) are one the most important recreational fishes in North America, and are also sought by anglers in many Idaho waters. There is extensive confusion surrounding the timing and interpretation of otolith zones, specifically, which zone represents fast growth and which represents slow growth. Further, otoliths are a lethal sampling method and regardless of population status, many fisheries biologists prefer to use no lethal sampling methods. To determine if the …

Beaver Reintroduction Correlates With Spotted Frog Population Restoration And Terrestrial Movement Patterns Of Newly Metamorphosed Columbia Spotted Frogs In The Owyhee Uplands Of Southwestern Idaho, Hallie Anne Lingo

Boise State University Theses and Dissertations

This thesis examines topics relevant to Columbia spotted frogs (Rana luteiventris) in the Owyhee Uplands of southwestern Idaho. First, I present a detailed discussion of both the ecology and conservation status of spotted frogs. Concerns about declining spotted frog numbers in the southern portions of the species’ range were first expressed in the early 1990’s. In response, several studies on the behavior and ecology of spotted frog have been conducted by Boise State University. In addition, the Idaho Department of Fish and Game monitors the status of spotted frogs in the Owyhees using an occupancy model developed and implemented in …

Understanding The Tradeoff Between Safety And Food Quality In A Mammalian Herbivore Specialist, The Pygmy Rabbit, Jamie Lyn Utz

Boise State University Theses and Dissertations

Conserving a sensitive animal species requires understanding the simultaneous tradeoffs between food and shelter within a landscape. Most management approaches only consider single factors like percent cover at landscape spatial scales. Quantifying the synergy between cover and food quality at a scale relevant to a foraging animal could better reveal the forces that shape habitat use. To better understand habitat use components, I investigated tradeoffs between predation risk and diet quality in a sagebrush endemic, the pygmy rabbit (Brachylagus idahoensis). This species is a rare example of a specialist herbivore that relies almost entirely on sagebrush for cover …

Raptors Present But Unobserved: Detectability At A Western Migration Watch-Site And Its Effect On Trend Analysis, Eric G. Nolte

Boise State University Theses and Dissertations

Annual counts of migrating raptors (Accipitriformes, Falconiformes) are used as indices of population size. Variation in the proportion of the raptor population counted may decrease precision of trend estimates, thereby reducing power of inference. The proportion counted is the product of sample coverage and probability of detection. It is possible to improve the power of trend analysis by the adoption of techniques, such as double-observer or distance sampling, which estimate the probability of detection. I used a dependent double-observer method to estimate detectability at the annual fall raptor migration count at Lucky Peak, Idaho, in 2009 and 2010. …

Yolk Androgens And Development In American Kestrel Nestlings, Melanie Dawn Berg

Boise State University Theses and Dissertations

Maternally derived yolk androgens affect many aspects of phenotypic development. To explore this phenomenon I injected clutches of American kestrels (Falco sparverius) with one of three different dosages of testosterone + androstenedione or with vehicle. Morphological measurements taken from nestlings 26 days after hatching showed no significant treatment effect. In 2007, nestlings with more yolk androgens had lower hatching mass and higher hematocrit levels 15 days after hatching than nestlings with less yolk androgens, but the effects disappeared by day 26. In 2008, there were no effects of androgens on mass or hematocrit. Because the results were not …

Diet And Behavior Of Ferruginous Hawks Nesting In Two Grasslands In New Mexico With Differing Anthropogenic Alteration, William Hanlon Keeley

Boise State University Theses and Dissertations

I analyzed regurgitated pellets, prey remains, and video recordings to describe Ferruginous Hawk (Buteo regalis) diet in two grasslands in New Mexico, USA, the Estancia Valley and the Plains of San Agustin, that differed in anthropogenic alteration. Video monitoring revealed Ferruginous Hawks provisioned nestlings with more biomass than pellet analysis estimates from the same nests. Three mammalian prey species, Botta’s pocket gopher (Thomomys bottae), Gunnison’s prairie dog (Cynomys gunnisoni), and desert cottontail (Sylvilagus audubonii)contributed similar proportions to Ferruginous Hawk diet in percent biomass while Botta's pocket gopher dominated diet in percent frequency. …